I think there's a potent future-nostalgia synthesis when a vision that grabbed you recedes into the past. Hangs over you like a dream. I still get a pang of excitement looking at a still from Alien or clips of the Terminator. I'm aware they're old, but they don't feel any less futuristic to me. The imagination factor's key. We've drones zipping all over the place, laser weapons, touchscreen phones, but they don't feel like "The Future" the way some tune or film from '98 does. They don't have the pull.
Part of it's down to contemporary depictions not feeling that distinct from the present. You look at some SF and the decor isn't far off a rich person's minimalist townhouse. The current vision's a dematerialised future. A sterile future. The older visions could be tactile and rugged. That's partly why they stick.